To help erase unsightly yellowing brought on by air pollution, India's crown jewel is being treated to the architectural version of a purifying facial masque.

The most grandiose monument ever to be erected in memory of a dead third wife, the Taj Mahal, will soon undergo a cleansing spa treatment of sorts for buildings, a process that involves archaeologists applying a layer of lime-rich clay over areas of the milky white marble mausoleum-cum-tourist magnet that have been yellowed by air pollution and smoke generated by a nearby oil refinery.

As reported by the BBC, this isn’t the first time that the Taj Mahal has undergone a beautification ritual “based on a traditional recipe which is used by Indian women to restore a natural glow to their faces.”

In 2008, a mudpack was applied to the exterior of the iconic domed 17th century tomb and the minaret-heavy complex surrounding it as part of an effort to reverse the telltale signs of air pollution that have ravaged the iconic edifice. And while the 2008 treatment, along with two similar previous mudpack applications in 1994 and 2001, have indeed helped to erase yellow staining and restore the Taj Mahal’s distinctive “glow,” the air pollution situation in the heavily industrial city of Agra, located in India’s northern state of Uttar Predash, is so bad that the mudpack application has turned into an every-few-years type of affair.

“Due to increasing pollution in the city, the white marble is yellowing and is losing its sheen," B M Bhatnagar of the Archeological Survey of India explained to the Press Trust of India. Bhatnagar goes on to explain that after the clay is plastered over yellowing areas of the monument, it's left to dry overnight. “When it dries the flakes are removed from the surface with soft nylon brushes and washed with distilled water to remove impurities sticking to the surface.”

Bhatnagar notes that the 2008 mudpack treatment cost around $24,000 and was carried out over the span of several months as to not interrupt normal tourism operations at the bustling UNESCO World Heritage Site which receives roughly 3 million visitors annually.

Situated on the banks of the Yamuna River, the uber-bucket list-y Taj Mahal was completed around the year 1653 as a tribute to Mumtaz Mahal, a Persian-born empress who died while giving birth to her 14th child with Mughal Emperor Shah Jhan. She was 40. The construction process, overseen by a grief-stricken Shah Jhan, is believed to have taken over two decades.

(Over at sister site TreeHugger, you'll find more sobering info on how years of unchecked development and pollution in and around Agra have taken a toll on the crown jewel of India.)